A MOLECULAR LENS FOCUSED ON UNDERSTANDING ALZHEIMER'S DISEASE HEALTH DISPARITIES

Abstract Alzheimer’s disease (AD), the most common cause of dementia in older adults, disproportionally affects African Americans (AA) with an incidence rate as much as three times higher, compared to other racial/ethnic groups. Multiple factors contribute to this racial disparity however, an in-depth understanding of the biological or genetic contributions does not exist. Compelling evidence indicate that genetic variants of the lipid transport protein, ABCA7, is more strongly associated with AD in African Americans. To understand how ABCA7 contributes to AD on the molecular level, we used a combination of structural and cell biology techniques. Our results suggest that the ABCA7 variant (T319A) reported to confer risk in AA, may contribute to AD by reducing the levels of phosphoinositol bisphosphate (PIP2), a phospholipid reported to be decreased in the AD brain. These results provide a framework for targeting mechanisms that increase PIP2 levels as an effective strategy mitigating AD disparities.


DIFFERENCES IN LIFE COURSE PATHWAYS TO DEMENTIA INCIDENCE FOR BLACK AND WHITE OLDER AMERICANS Mateo Farina, University of Southern California, Los Angeles, California, United States
Black Americans are 2-3 times more likely to have dementia than White Americans. Studies have evaluated how differences in exposures to life course risk factors, such as level of education, may be contributing to this disparity. When using this approach, substantial reductions in cognitive health inequality across race were accounted for, but not completely explained. However, this research assumes an underlying similarity in life course pathways to cognitive impairment risk across race groups. We used longitudinal data from the Health and Retirement Study (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016) to evaluate life course pathways to dementia risk across race groups. We find substantial differences across race groups. Dementia risk for older black adults is greatly shaped by southern birth and education. For older white adults, adulthood factors such as wealth, health behaviors, and cardiometabolic conditions has a greater role. Our findings support calls for a closer examination of within group analysis among minoritized populations.

VARIABLE PREDICTORS OF COGNITIVE PERFORMANCE WITHIN ETHNIC/RACIAL GROUPS USING A COMPUTERIZED COGNITIVE BATTERY Kacie Deters, University of California, Los Angeles, Inglewood, California, United States
The Computerized Cognitive Composite (C3) may provide an efficient assessment of early cognitive impairment to inform early interventions and screening criteria for Alzheimer's disease clinical trials. The C3 battery, which includes the CogState Brief Battery, has components assessing memory, reaction time and aspects of executive function. The battery has little demand for spoken language and may reduce the sociocultural biases of traditional paper-and-pencil tests. The goal of this project was to determine demographic and genetic predictors of cognitive performance on the C3 battery across different ethnic/racial groups. We examined 4,026 cognitively normal participants (self-identified non-Hispanic Black, Asian, or White; Hispanic) at baseline visit from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) clinical trial. Linear models were performed to examine the association of C3 and years of age, years of education, gender/sex, and Apolipoprotein E (APOE) genotype, within ethnic/racial group. We found variation in demographic and genetic risk factors that predicted cognitive performance within ethnic/racial groups. These findings highlight the importance of within group analysis to identify risk factors for cognitive impairment. Social isolation negatively impacts cognitive health. Although the mechanism is not fully understood, cultural values such as familismo, may help partially explain this susceptibility. Our work sought to understand how cultural differences in objective and perceived social isolation affect cognitive performance of Hispanic/Latinos (H/L) compared to non-H/L Whites. In our first study, using the TARCC dataset, objective covariates of social isolation (i.e. marital status, number of children, number of siblings, living situation), significantly explained a higher percentage of the variance in composite cognitive scores of H/Ls, compared to non-H/L Whites. In our second study, using the HABS-HD dataset, personal and health characteristics influenced the effect of perceived social isolation on cognitive status among older adults. Furthermore, compared to non-H/L Whites, fewer factors accounted for greater variance in cognition of H/Ls. Results suggest enhancing social connectedness of H/L older adults could be a modifiable factor for prevention of cognitive decline.

A MOLECULAR LENS FOCUSED ON UNDERSTANDING ALZHEIMER'S DISEASE HEALTH DISPARITIES Jamaine Davis, Meharry Medical College, Nashville, Tennessee, United States
Alzheimer's disease (AD), the most common cause of dementia in older adults, disproportionally affects African Americans (AA) with an incidence rate as much as three times higher, compared to other racial/ethnic groups. Multiple factors contribute to this racial disparity however, an in-depth understanding of the biological or genetic contributions does not exist. Compelling evidence indicate that genetic variants of the lipid transport protein, ABCA7, is more strongly associated with AD in African Americans. To understand how ABCA7 contributes to AD on the molecular level, we used a combination of structural and cell biology techniques. Our results suggest that the ABCA7 variant (T319A) reported to confer risk in AA, may contribute to AD by reducing the levels of phosphoinositol bisphosphate (PIP2), a phospholipid reported to be decreased in the AD brain. These results provide a framework for targeting mechanisms that increase PIP2 levels as an effective strategy mitigating AD disparities.

GIVING AND GETTING ACROSS THE GENERATIONS: NEW INSIGHTS INTO INTERGENERATIONAL TIES Chair: Deborah Carr Discussant: Deborah Carr
Population aging raises debates about who will care and provide for older adults, while shifting economic and family patterns suggest that young adults may require ongoing support from their (grand)parents. These five papers use diverse methods and data to shed new light on upward and downward intergenerational exchanges. Fingerman and colleagues use data from a small racially diverse sample of young adults (ages 18 to 29) providing care to grandparents. They document psychological benefits yet potentially harmful life course disruptions (e.g., education). Wiemers and co-authors use the Health and Retirement Study Core and COVID-19 Module to document how adult children's transfers of time, money, and coresidence changed in response to the COVID-19 pandemic. Minoritized and lower SES older adults were less likely to receive help from family members, due to children's constraints. Whitworth documents disparities in the types of support college students receive from midlife parents, using the Panel Study of Income Dynamics Transition to Adulthood Supplement. Higher SES parents tend to provide financial support, whereas lower SES parents provide coresidence. Silverstein et al. use multigenerational data from Longitudinal Study of Generations. They find religiosity of parents during the offspring's adolescence affects their cognitive and behavioral religiosity in later life. Avni uses cross-national attitudinal data from the International Social Survey Programme (ISSP) and finds that Americans believe family should be responsible elder care, whereas Israelis and Germans believe the government should provide care. The discussant highlights implications of the study results for research and policies regarding intergenerational relations.

CAREGIVING FOR AN OLDER RELATIVE IN YOUNG ADULTHOOD
Karen Fingerman 1 , Shiyang Zhang 1 , Zexi Zhou 1 , Yee To Ng 1 , Kira Birditt 2 , and Steven Zarit 3 , 1. The University of Texas at Austin,Austin,Texas,United States,2. University of Michigan,Ann Arbor,Michigan,United States,3. Pennsylvania State University,Pittsburgh,Pennsylvania,United States Caregivers are typically viewed as midlife or older individuals, but nearly 25% of self-identified caregivers are young adults (aged 18 to 29). We report findings from a small study of Hispanic/Latinx, African American, and Asian American young adult caregivers, using: quantitative and open-ended assessments and weekly diary surveys. We assessed caregiving tasks young adults provide, rewards, and detriments of providing care. In open-ended responses, young adults described their caregiving roles as emotional as well as hands on, and reported filling in for other caregivers who could not help. They reported goal disruptions (e.g., education, romantic ties) associated with caregiving, but felt they were repaying debts to their grandparents through caregiving. Diary data document vicissitudes in weekly caregiving experiences and well-being. Discussion focuses on the unique implications of caregiving ties between young adults and their grandparents when the grandparent incurs physical or cognitive health impairments. Merril Silverstein, Joonsik Yoon, RianSimone Harris, and Woosang Hwang, Syracuse University, Syracuse, New York, United States The development of religiosity in later life has its origins in earlier phases of the life course, yet few studies have investigated the contribution of early religious exposure to religious beliefs and behaviors in old age. This investigation uses multigenerational data from the Longitudinal Study of Generations taken from 385 baby boom children, 16-26 years of age, and their parents in 1971, and follows the children's religious orientations into midlife and old age. Guided by intergenerational transmission and path dependency perspectives, we found that parents' religious intensity in 1971 strengthened their children's cognitive and behavioral religiosity in later life as mediated by children's early and midlife religiosity. Our results demonstrate both intergenerational transmission followed by temporal stability in religious belief and practice. Evidence suggests that parental influence creates religious momentum in their children that carries from adolescence/young adulthood through the unfolding of their lives into old age.

CROSS-NATIONAL DIFFERENCES IN ATTITUDES TOWARD FAMILY AND GOVERNMENTAL SUPPORT FOR ELDER AND CHILD CARE Elinore Avni, Boston University, Boston, Massachusetts, United States
Population aging in wealthy western nations has raised concerns about who will provide care to older adults. At the same time, the rise of single parenthood and dual-career families has heightened the need for childcare. As governments and families face challenges in meeting these dual needs, this study compares responses to the question of "who should primarily provide" eldercare and childcare across three countries: the US, Germany and Israel. Analysis of 2012 International Social Survey Programme data reveals that while persons in the US endorse family as care providers to both older adults and children, Israelis endorse government as eldercare providers yet family as the source of childcare provision. German respondents prefer both government and family as childcare providers, yet believe the government should provide eldercare. The paper discusses how crossnational differences in attitudes toward care are associated with cultural and socio-economic characteristics, and highlights implications for policy and practice.